Methods for determining the angle-of-rotation position of a shaft of an internal combustion engine are known. In the case of a crankshaft in particular, determination of the crank angle is of great importance because important sequences in operation of the internal combustion engine, e.g., fuel injection or generation of an ignition spark, are usually controlled individually for each cylinder as a function of the crank angle. To determine the crank angle, it is known, for example, that incremental sensors may be provided on the crankshaft and/or camshaft. These are usually sensor disks, i.e., sensor wheels, having incremental marks which in interaction with a sensor in a stationary position in relation to the engine block permit a determination of the angle-of-rotation position of the crankshaft. The incremental marks on the sensor disk are often designed as a sequence of teeth and both spaces, and the changes between tooth and that tooth space and/or tooth space and tooth, i.e., the tooth flanks, are detected as tooth signals by a sensor. It is also known that an enlarged tooth space, i.e., a tooth gap, may be created by omitting at least one tooth, and the absolute angle of the shaft may be determined with each revolution of the shaft on the basis of this tooth gap.
In the methods for determining the crank angle, 6°-sensor wheels having a tooth gap are often used. These are sensor wheels which have a sequence of 3°-wide teeth and 3°-wide tooth spaces, with a total 15°-wide tooth gap being created at a position along the circumference by omission of two adjacent teeth. Such a sensor wheel has a total of 58 teeth. However, the maximum possible resolution with this configuration is not sufficient for modern methods in which the crank angle is used as a processing parameter. DE 100 17 107 A1 describes a method in which precise angles are determined from the time difference between two successive teeth, these angles not being affected by tolerances in the sensor wheel. However, this reliable method does not allow any improvement beyond the limits of resolution due to the design.